Long ago, in a world long gone, there was a race of parasites that would parasitize a host's brain and feed on his emotions and memories until the day he died, this race was Known as the Mind Parasites or Mind eaters, the locale populace of this world never paid attention to this parasitic worm race.
But on an unfortunate day an evil creature had turned its attention to this world, and this evil creature was Cthulhu the Old One, While corrupting this world and consuming it, Cthulhu's attention was drawn to this race of Mind Parasites, what he liked most was to play with mortal's minds and make them crazy enough to worship him forever.
In his endless madness, the Old One restructured this race of Parasites and blessed them with evolution and Potential, his own essence flowed in their veins making these creatures excellent at playing with emotions, memories, flesh and blood.